Mechanism for truing and dressing grinding-wheels



E. R. CONNERS.

MECHANISM FOR mums AND DRESSING GRINDING WHEELS.

APPLICATION FILED OCT. Z. {920.

Patented N0v.- 1, 1921.

2 SHEETS-SHEET 1.

E. R. CONNERS.

MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS.

AP LICATION FILED OCT. 7. 1920- 1,395,393. Patented Nov. 1, 1921.

2 SHEETSSHEET 2.

9& 15

' abrading part,

EDWARD R. CONNERS, OF' CINCINNATI, OHIO, ASSIGNO TRUING MACHINE AND 'IOOL COMPANY, OF CINCINN 'I'ION OF OHIO.

R TO THE PRECISION ATI, OHIO, A CORPORA- MECHANISM FOR TRUING AND DRESSING GRINDING-WHEELS.

Specification of Letters Patent.

Patented Nov. 1, 1921.

Application filed October 7, 1920. Serial No. 415,402.

To all whom it may concem:

Be it known that I, EDWARD R. CoNNERs, a citizen of the United States, residing at Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Mechanism for Truing and Dressing Grinding-Wheels, of which the following is a specification.

y invention relates to mechanisms for truing and dressing grinding wheels, such as emery wheels, employed in grinding or polishing machinery for grinding or polishing the surfaces of-metal in precision grinding. A usual means heretofore employed in truing and dressing operations on grinding wheels has been a diamond tool comprising a diamond made to contact the grinding surface of the grinding wheel, but diamonds have become very scarce and very expensive.

It is the object of my invention to provide means to dispense with the use of diamonds for these purposes.

It is the further object of my invention to provide a rotary a-brading part arranged to contact the grinding surface of the grinding wheel in such manner as to cause rotation to be imparted to the rotary abrading'part by the rotating grinding wheel, and means whereby such rotation is maintained during intervals of absence of contact between the rotary abrading part and the grinding wheel; further, to provide a structure of this character with. means to present the rotary abrading part in various positions and at various angles to the rotary grinding wheel; further, to provide a truing and dressing device having an exposed rotary and a fiy-wheel arrangement therefor located in a casing, and positioning means for the casing, and, further, to provide novel truing and dressing mechanism of the character mentioned.

The invention will be further readily un- I 1 i derstood from the following description and claims, and from the drawings, in which latter:

Figure 1 is a side elevation, partly broken away, of a grinding machine having my in ven en applied thereto.

' 2 is a plan view of the same.

is an end elevation of the same.

i" g. 4 is a detail of the same in vertical section, taken on the line 4.- i' of Fig. 2,

on the frame on 'guideways 26. is journaled in the carriage in bearings 28, and has a grinding-wheel 29 releasably secured in suitable manner thereto. carries a long pulley 31, lengthwise of the carriage, and is arranged to be operated. by a belt 32, received over said pulley and a pulley 33 on a drive-shaft.- 34, journaled in frame, and suitably operated by tight and loose pulley 36.

meshes with r journaled in b The shaft rotatable looser Fig. 5 is a ide elevation of my improved dressing and truing device.

1g. 6 is a plan view of the same, showing the grinding wheel in relative position thereto, the grinding wheel being partly broken away; and,

F 1g. 7 is a similar View, the dressing and truing device being shown in horizontal section on the line 77 of F' 1g. 4. My invention 1s an improvement on the vices for truing and dressing grinding wheels.

November 2, 1917, and Serial No.

I have exemplified my invention in connection with a rotary grinding machine, having a rotary grinding wheel, which reciprocates lengthwise of its axis of rotation, and

a rotary support or table for the work to be 7 ground. I have shown an exemplifying device of this character, main frame 11, on which there is a worksupporting slide 12, adjustable up and down on guideways 13 of the main frame, for instance, by mean of a raising and lowering screw 14, threaded in a threaded bearing 15 rigid with the frame, and journaled in a bearing 16 of the slide. bevel-gear 17 fixed thereto, with which a bevel-gear 18 meshes, the latter being fixed to a shaft 19, journaled in bearings 20 in the slide, and having a hand-wheel 21 for rotating the same.

which comprises a The screw has a A carriage 25 is arranged to reciprocate A shaft 27 It also which extends bearings 35 in the main A gear 4-1 i r A6 4 i n, held in end-1 45, 46. A lever 51 is pivoted to the main frame on a pin 52, and is provided with a fork 53, the tlnes of which are received in an annular groove 54 in the clutch-collar. The lever is arranged to be contacted by tappets 56, 57, adjustably secured in suitable positions along a slot 58 in the side of the carriage, for reversing the directions of movement of the carriage. The lever may also be provided with a handle 59 for manual manipulation and shifting of the clutchcollar, whereby to reverse the directions of movement or to stop movement of the carriage.

The gear 46 meshes with an intermediate gear 61, and the latter meshes with a gear 62, fast on a shaft 63, journaled in bearings 64 in the main frame. The gear 45 meshes with a gear 65 also fixed on the shaft 63.

The shaft 63 has a bevel-gear 71 fixed thereto. It meshes with a bevel-gear 72 on a shaft 73, journaled in bearings of the main frame. A spur-gear 75 is fixed to the shaft, and meshes with a bull spur-gear 76. The latter in turn meshes with a rac 77 fixed to the carriage. The bull spur-gear is fixed to a shaft 78, journaled in bearings 79 of the main frame, and has handles 80 thereon for moving the carriage in reverse directions by hand when the clutches 48, 49, are out of en agement.

The drive-shaft has a gear 81 fixed thereon, which meshes with a gear 82. The gear 82 is normally loose on a shaft 83, journaled in bearings 84 of the mainframe. A clutchcollar 85 has suitable spline and key connection with said shaft. A clutch 87 is located between said clutch-collar and the ear 82. When this clutch is in engagement the shaft 83 rotates with the gear 82. A clutch 86 is located between the clutch-collar and the bearing 84. When this clutch is in engagement, rotation of the shaft 83 is prevented to prevent rotation of the work-supporting table. A fork-lever 88 suitably pivoted to the main frame and received in an annular groove 89 in the clutch-collar 85 is arranged to engage either clutch or to hold the clutch-collar 1n disengaging relation.

A bevel-gear 91 is fixed to the shaft 83. The bevel-gear 91 meshes with a bevel-gear 92, which is journaled in endwise fixedrelation in'a bearing 93, on a bracket 94 extending from the frame, through an opening 95 in the slide 12.

An upright. shaft 101 is slidable in the hub of the bevel-gear 92, and is journaled in a bearing 102, located in a bracket 103, extending from the slide, and a bearing 104 in the upper part of said slide. The bevelgear 92 has spline and key connection 105 with the upright shaft. The upright shaft 101 has thereon a. work-support or table 108, which rests on the bearing 104. The table is arranged to have the work to be ground suitably secured thereto, whereby the work, when the table is rotated, rotates under the grinding wheel. The vertical adjustment of the slide 12 is such that the work is brought within range of the grinding wheel. The table preferably rotates in a trough 109, arranged to receive and carry away the water or other lubricant received in suitable manner against the grinding wheel or over the. work. The trough is part of the slide.

The table may be in the form of a magnetic chuck, arran ed to be magnetized, for instance, by suita le magnetic coils, indicated at 112, comprising cores and suitable windings, a suitable switch controlling the magnetic force in the magnets from a suitable source of power.

While the work which is secured to the table is being ground, the carriage 25 is caused to move back and forth on its guides, by means of the shifting of the clutches 48, 49, so as to move the grinding wheel back and forth in contact with t e work for k grinding the same while the table is being rotated.

The grinding wheel will in course of time become impregnated with particles of dirt and metal from the work being operated on, and become comparatively smooth and glossy, thereby losing its grinding effect. I have, in the present means for removing the foreign substances creating such smooth or glossy eflect from the surface of the grinding wheel, such means including a rotary abrading part 116, shown as an abrading wheel.

I have in a separate application, Serial No. 415,403. filed October 7, 1920, copending herewith, shown, my invention in connection with an abrading stud or pencil.

The abrading wheel is preferably of smaller diameter compared to the diameter of the grinding wheel, and is preferably a caiborundum wheel, and of a texture much harder and preferably coarser than the texture of the grinding wheel to be trued or dressed, and is arranged tooperate pn the grinding wheel to remove the foreign sub stances located in'the recesses and poresof the grinding surface of the grinding Wheel, and to sharpen the surface grains of the grinding surface of the grinding wheel. for again rendering the grinding wheel sharp and in proper condition for grinding, and also for truing the grinding wheel, to again cause it to be the form of a true cylinder, when such form is employed.

described and claimed inv exemplification, shown' It is necessary for obtaining true, accurate and desirable grinding, that the grinding Wheel be maintained in proper grinding condition. The grinding wheel may in course of operation become out of true, that is to say, its periphery or grinding surface will no longer be a perfect cylinder, or the grinding surface may in whole or in part have become polished or substantially inactive for grinding, by having its cavities filled with the material being ground, and its granular structure dulled, in either or any of which cases it is necessary to repair the grinding surface of the grindingwheel, which is effectively done by means of my invention.

The abrading wheel is shown secured to a shaft 121, received in a casing 122, part of which is shown as a barrel 123. A bushing 124 is located in the barrel, and is fixed therein by means of a set-screw 125. Ball bearings 128, 129, are located at the respective ends of the bushing, these ballbearings being combined radial and endthrust bearings, and each comprising an inner ring 131, having an annular ballgroove 132 therein, and an .outer ring 133, having an end-thrust ball-groove 134. The latter rings are oppositely disposed and the construction is such that end movements of the shaft are prevented. The inner rings are fixed to the shaft 121. Balls 135 are located between the rings of the respective bearings. A washer 137 is received about the shaft and against the inner ring of the ball-bearing adjacent to the rotary abrading part. An absorbent washer 138, for instance of felt, is located between the washer 137 and the ball-bearing. The means provided for releasably securing the abrading Wheel to the shaft are shown as a washer 141, received against an annular shoulder 142 on the shaft, the abrading wheel being received over the reduced end 143 of the shaft against said washer. A washer 144 is received at the outer side of the abrading wheel, and a nut 145 is threaded to the outer reduced end of the shaft 121, for clamping the rotary abrading part in place.

The shaft also carries a fly-wheel 148 secured thereto, as by means of providing the shaft with a reduced end 149 having a threaded end 150. The fly-wheel has a central hole through which the reduced end of the shaft is received, the fly-wheel impinging the annular shoulder 151 on the shaft. A key 152 in the shaft is received in a slot 153 in the fly-whe'el for holding the parts against relative rotation. A nut 154 clamps the fly-wheel in place. The fiy-wheel has a heavy rim 155 whichprojects inwardly to surround the ball-bearing adjacent thereto. placing said ball-bearing in the cup of said flywheel, to place said ball-bearing in th line of radial stresses of said fly-wheel to provide ease and smoothness of running of the rotary abrading part. The fiy-wheel maintains effective rotation of the rotary abrading part between intervals of contact in the truing or dressing operation. The barrel is provided with an enlargement 158, forming a cup received over the fiy-wheel, a cover-plate 159 being preferably releasably secured to the cup as by screws 160, in order to inclose the fiy-wheel in the cup and to form a closed cover or casing for the fiy-wheel, the shaft and its bearings, so as to hold the same free of contact by the water or other lubricant which may be used in connection with the grinding operation.

The casing may be provided with a pedestal 161 having a comparatively extended base 162. The parts are of metal, and the base is arranged to be placed upon the magnetic table so as to be held firmly by the magnetic force in the same in the desired position for the operation which is to be performed when truing or dressing the grinding wheel. The firmness of contact between the rotary abrading part and the grinding wheel is adjusted by the raising or lowering of the table on which the abrading device is mounted. The truing and dressing device may be placed in various positions on the magnetic table or chuck. whereby to arrange the rotary abrading part or wheel with its abrading surface parallel with the grinding surface of the grinding wheel, or at an angle thereto.

Different degrees of fineness of truing or dressing are obtained by various relations. If the rotary abrading wheel is parallel with the grinding wheel, that is to say, their axes of rotation are parallel with each other. a dressing is accom )lished which leaves the grinding wheel with a finer surface. whereas if the abrading wheel is placed at an angle with relation to the grinding wheel, the dressing of the grinding wheel will be coarser, the coarseness of dressing depending on the extent or degree of angularity between the parts. The greater the angle the coarser will be the dressing. A substantial angular relation is therefore desirable upon truing the grinding wheel. for instance. as shown in the drawings, while a relation approximating parallelism is desirable when dressing the grinding wheel, depending on the fineness of grinding surface desired on the grinding wheel.

The base is also preferably provided with slots 163, through which bolts or screws may be received for clamping the frame in suit able positions when no magnetic chuck is employed.

When truing or dressing the grinding wheel, the grinding wheel. in the present exemplification, is caused to rotate. and to reciprocate lengthwise of its axis of rotation,

across the face of the abrading wheel. The grinding wheel is instanced as rotating in the direction of the arrow at and the abrading wheel is instanced as rotating in the direction of the arrow 6. During the time that the abrading operation takes place, the table is preferably stationary, as by releasing the clutch 87, and engaging the clutch 86, acting to lock the upright shaft 101.

The rotary abrading part is normally quiescent. The grinding wheel is preferably reciprocate-d, during the truing or dressing operation, so as to pass beyond the rotary abrading part in each direction of its reciprocating movement, the grinding wheel being received in the gap 164 between the guides 26, if desired. The fly-wheel maintains effective rotation of the rotary abrading part between the time the grinding wheel passes beyond'the rotary abrading part and the time that the grinding wheel next makes contact with the rotary abrading part, so that, when such contact is made, the rotary abrading part is rotating with force for effective truing and dressing effect on the grinding wheel. I

Contact of the rotating grinding wheel with the peripheral face of the abrading wheel causes the abrading wheel to rotate, the rotation being equalized and maintained by the fly-wheel, so that when the grinding wheel passes outside or partly outside the range of contact with the abrading wheel, the rotation of the abrading wheel will continue with substantial force until contact or full contact is again made with it in the reverse reciprocation of the grinding wheel. The rotation of the rotary abrading part is also rendered even or uniform by the presence of the fly-wheel, regardless of whether the rotary abrading part be an abrading wheel, as shown in the drawings, or an abrading pencil, as exemplified inmy aforesaid applications Serial No. 366,970 and Serial No. 415.403.

I have exemplified the abrading wheel as positioned at an angle to the grinding wheel. and in practice I prefer a relative angular position between the wheels. the degree of angularity increasing with the coarseness of the dressing surface desired on the grinding wheel. A wiping movement is thus imparted between the impinging surfaces of the abrading wheel and the grinding wheel at the points of impingment, there being a differential movement between the contact surfaces of said wheels at the points of contact which acts to wipe or draw the dirt, particles of metal, and other foreign substances, out of the recesses or pores of the grinding surface of the grinding wheel and to sharpen the granules of the grinding surface. by the wiping action of a portion of the contacting line' of the abrading surface, which 1 moves in a direction reverse to the direction of rotation of the grinding wheel and crosswise of the grinding face of said grinding wheel.

7 The danger of gouging into the surface of the grinding wheel is eliminated by employment of my improved device, and the diameter of the abrading wheel being substantially less than the diameter of the grinding wheel, the drawing or brushing action thereof is enhanced.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent is:

1. In mechanism for truing and dressing grinding wheels, the combination of a grinding wheel, a rotary abrading part, a support therefor, and a rotary magnetic chuck for adjustable positioning and holding of'said support with relation to said grinding wheel.

2. In mechanism for truing and dressing grinding wheels, the combination of a grinding wheel, a rotary abrading part, a support for the latter, a rotary magnetic chuck coacting with said support for holding said support in selective positions whereby to control angular relation between said rotary abrading part and said grinding wheel, and means for adjusting said magnetic chuck and said support thereon toward and from said grinding wheel.

3. In mechanism for truing and dressing grinding wheels, the combination of a grinding wheel. a rotary abrading part, a supportfor the latter; a rotary magnetic chuck coacting with said support for holding said support in selective positions whereby to control angular relation between said rotary abrading part and said grinding wheel, means for locking said rotary magnetic clinch. and means for causing reciprocation between said grinding wheel and said rotary abrading part.

4. In mechanism for truing and dressing grinding wheels, the combination of a grinding wheel, means for rotating said grinding wheel, a normally quiescent rotary abrading part means for positioning the latter with relation to said grinding wheel. means for causing reciprocation between said grinding wheel and said rotary abrading part. and a fly-wheel for said rotary abrading part, said rotary abrading part and said fly-wheel rotated solely by said grinding wheel.

5. In mechanism for truing and dressing grinding wheels, the combination of a grinding wheel. means for rotating and reciprocating said grinding wheel, a normally quiescent rotary abrading part, means for adjusting the latter with relation to said grinding wheel, and a fly-wheel for said rotary abrading part, said rotary abrading part and said fly-wheel rotated solely by said grinding wheel.

6. In mechanism for truing and dressing grinding wheels, the combination of a grind ing wheel, a normally quiescent rotary abrading part, said rotary abrading part arranged for coaction with said grinding wheel, means for reciprocating said grinding wheel to pass in both directions beyond said rotary abrading part and whereby to rotate said normally quiescent rotary abrading part solely by contact of the rotating grinding wheel with said rotary abrading part, and a fly-wheel for said rotary abrading part arranged to maintain'eifective rotation of said rotary abrading part between the times of cessation and renewal of rotating force applied to said rotary abrading part by said grinding wheel.

7. In mechanism for truing and dressing grinding wheels, the combination of a rotary abrading part for the grinding surface of the grinding wheel, said rotary abrading partbeing normally quiescent, and a flywheel acting on said rotary abrading part to maintain its rotation, said rotary abrading part and said fly-Wheel rotated solely by the grinding surface being treated.

8. In mechanism for truing and dressing grinding wheels, the combination of a rotary abrading part, a fly-wheel therefor, and a closure-casing received about said fly-Wheel, said rotary abrading part and said fly-wheel being normally quiescent and rotated solely by the grinding surface.

5 In mechanism for truing and dressing grinding wheels, the combination of a normally quiescelnt rotary abrading part, a. shaft, releasable securing means between said rotary abrading part and said shaft, a bearing for said shaft, and a fly-wheel received about said shaft and said bearing.

10. In mechanism for truing and dressing grinding wheels, the combination of a rotary abrading part, a shaft therefor, bearing means for said shaft, means for attaching said bearing means relatively to the grinding wheel, and a fiy-wheel about said shaft and said bearing means for maintaining rotation of said shaft and said rotary abrading part.

11. In mechanism for truing and dressing grinding wheels, the combination of a rotary abrading part, a casing comprising a barrel, afshaft for said rotary abrading part having bearing in said barrel, a fly-wheel on said shaft, and said casing comprising a closure about said fly-wheel;

12. In mechanism for truing and dressing grinding wheels, the combination of a casing comprising a barrel and an enlargement, a bushing in. said barrel, a ball-bearing in said casing at each end of said bushing, a shaft in said ball-bearings comprising means at one end thereof for attachment of a rotary abrading part, and a fly-wheel at the other end of said shaft in said enlargement of said casing. 3

13. In mechanism for truing and dressing grinding wheels, the combination of a casing comprising a barrel and an enlargement, a bushing in said barrel, a ball-bearing in said casing at each end of said bushing, a; shaft in said ball-bearings comprising means at one end thereof for attachment of a rota abrading part, and a fly-wheel at the other end of said shaft in said enlargement of said casing,said fly-wheel being cup-shaped with its outer annular portion extending toward said rotary abrading part and received about the proximate end of said bearings.

14. In mechanism for truing and dressing grinding wheels, the combination of a casing comprising a barrel and a hollow enlarge- I ment therefor, a bushing insaid barrel, a ballbearing at each end of said barrel at each end of said bushing, an absorbent washer in one end of said barrel for protection of one of said ball-bearings, a shaft in said bearings, means thereon at one end thereof for attachment of a rotary abrading part, and a fly-wheel at the other end of said shaft in said hollow enlargement.

In testimony whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

EDWARD R. CONNERS.

In presence of- J. E. MALONEY, C. J. HEOKERT. 

